Many pickup trucks are designed with a sliding glass window located behind the heads of the driver and passengers. The windows are normally disposed in tracks and have right and left side portions which slide laterally, thereby providing an opening in the center portion of the window. The window is located over the rear wall of the cab which is, in turn, spaced slightly forward of the front wall of the truck bed.
Many trucks of this type are designed to receive a cap which covers the bed. The cap is basically a shell with a front wall portion and an open bottom portion, the lower edges of which engage and are secured to the upper edges of the truck bed. The front wall portion may be provided with windows opposite the windows in the cab. The bed can thus be used for transporting materials, equipment, and in some cases, people, while protecting what is being transported from the elements.
One example of this type of arrangement is found in U.S. Pat. No. 4,093,301 to Kwok for a Movable Door for a Vehicle. The invention shows a truck body having a sliding door and window in the rear of the cab which is aligned with a sliding door in the camper portion. The combination permits access to the camper from the cab of the truck. This type of camper, however, normally is self-contained with a front wall and a floor, and is designed as an essentially complete enclosure.